Stretcher jack



Dec. 26, 1933. J. M. ANDREW STRETCHER JACK Filed May 9, 1932 [/v VEN TOR /r/G. j

PIENT' JOFKF invention relates to` telescope jacks in general and more particularly. to stretcher jacks adapted to spana space between opposed walls or supports.

their supportsand may. carry substantial weight,

Adjustment of such jacks to proper length before their opposite ends contact with the opposed-supporting 'walls is ytiresome andi necessitatesfuse of lheavy parts such'as screw rods, ratchetrods'and so' forth, which materiallyincrease weight and cost of these jacks. The general object ofthe present'invention is tolprovide a stretcher jack with normally disengaged clutching means .adapt-v 'led to be engaged for interconnection of the telescoped' par-ts of the jack with each other; only` when,torsionalustrains or stresses are appliedto the jack; thus permitting quick manual adjust-V ment oftheljack to proper size by longitudinal shifting of the telescoped Vpartswith respectto eachother andcoupling of thel telescoped parts by turning these'parts with'resp'ect to each other a telescope stretcher jack with tiltable' clutching meansfrotatably andlaxially'shiftablyiinterconl v y bar l-int'erengagedA with'theflange of said f nectedwith'one of the telescoped'elements and slidably and nonrotatably engaged with `another of the ftelescopedelements" to effect tiltingand vention consists in theA constructionand novel Y combination of parts fully described hereinafter, illustrated in the accompanying drawing, and

pointed out in the claims appended hereto, it be' ing understood that various changes the form, proportion, size and minor details of construction within the scope of the claims, may be Aresorted to without departing from the spirit of I the invention.

A In the drawing forming a part hereof: Y

ment of the improved telescope stretcherjack; Figure 2 is a view similar to Figure 1 with the clutch mechanism in engagement for coupling the telescoped parts of Vthe jack; Y f

Figure 3 is a longitudinal view of the jack extended to a length different fromthatshownin Figures 1 and v2; I

Figure 4 is a sectional view on line 4 4 of Jacks of the kind described are self supporting, l*when 'rigidly clampedy between v connected with tubing 2,-which mechanism ern-*f vpushing of disk 9 by means of screw l8 induced by Figure A5 is a sectional viewon line 5--5.of Figure -1; and Y 1- YFigure 6 is afsectional'view Lonline 66 of Figureil. s f In the embodiment of the invention fas, shown in the drawing,vthe telescope stretcherjack inj cludes two sleeved tubings 1 and 2 axially shift--y able with respect to each other," which may carry at their outer ends backing discs 4' and 5 respectively, padded by,` friction coverings'3.- Backing f disk 4 is rigidly securedto tubing 1,whereas disk Y 5 is pivotally engaged lwithtubing 2, Acarrying close to its outer end adisk 12,Which1is weldedtoV tubing-2 -and pivotally supports disk by means f of a loose rivet 1.3. A washer14i's arranged be-f-v tween disk 12 and 'backing'memberivto 'decrease 'frictionrbetween said velements-.during rotation with respect to each other.l Disk '4 centrally sup-V Y ports one endv of a bar 6 which is preferably'of rectangular cross section and,A alt/its other end fixed 75 to a round disk 7, slidably arrangedwithin tubing2. nBar r6 axially extends through val screw and clutching mechanism C supported by .andvr bodies a nut member 1'1, rigidly secured to-tubing iziby means Iof screwsll, a' flangedv screw member 8 interengaged withsaid nut 11, a stress screw memberrand a clutching disk 9. also interengaged Yvvithr said stress bar. .A circular axial passage 15 in screw ,member 8 permits rotation thereof with respect to-rectangular bar 6, while'a slot 176 in flange 8 of said screw member transmits'slightest rotation of said screw member to stress bar 10 and therewith to clutch disk 9, slotted at 17 for v'engagement withfsaid stress bar. An `axial rectangular perforation v18 in clutch disk 9 fits bar 6 and permits Vaxial shifting of said disk on said bar but prevents rotation between said disk and bar. Slots 19 and 20 in stress bar 10 interengage with slot 16 of ilange 8 of kscrew vmember 8 and slotV 17 of clutch disk 9 respectively to prevent axial shifting of stress bar 10 with respect to screw 8 and clutch disk 9.` Slot 19' is rectangularlyshaped to iit angeuno; 8', whilefslot 20 embodies an inclined wall 21 and a straight wall 22 to permit. tilting and straightening of said clutch disk during clutching and clutch releasing action of disk 9. Thus anticlockwise rotation of tubing 2 forces Ydisk 9 to a tilted position in which the sharp edges of the rectangular perforation 18 thereof bite :into rod 6, and securely coupledisk 9 to rod no" 6, whereas pulling of disk 9by means, of' screw 8, induced by clockwise rotation of tubing 2 forces said disk to its straightened position, as straight wall 22 and the end wall 25 of tubing 2 engage such disk and straighten same up. In case disk 9 is in its straightened position the tubings 1 and 2 may readily and easily be shifted with respect to each other, without interference of the clutch mechanism see Figures 1 and 3 which show the shifting of said tubings, with respect to each other when clutch disk 9 isin straight cned position. Tilting of disk 9 is induced by rotation of tubing 2 in anticlockwise direction. Thus, when the tubing l is held stationary and' the tubing 2 is rotated counter clockwise, the

stress bar 10 holds the head or ilange 8' of screi'v'v 8 so that it cannot rotate with nut ll'and also causes a torsional force on clutch disk v9, thus affecting frictional locking on bar- 6. As tubing 2 and therewith nut 11 rotates on screw 8 the .in-

ner open end 25 of tubing 2 moves away from clutch disk 9, and screw A8 through its ange', Apushes longitudinally against stress bari 1G and forces said clutch disk 'out' .of its `straightened or Vertical position into tilting and locking posi-v tion on bar 6.

Suiiicient force can then be exerted .by con-V tinuing to rotate tubing 2, While holding tubingl stationary to apply enough pressure through pads 3, 3 so that the stretcher jack and `v its load -will be sustained between two opposite surfaces or Walls. Y f

Clockwise rotation of tubing 2, while holding tubing 1 stationary moves nut 1-1 along screw 8 toward the head or flange 8 of the screw 6 Vuntil fthe open end 25 of the tubing 2 straightens coufof said tubes for forcing said tubes in oppositey directions and automatically actuated coup-ling means between said latter means andtheother of said tubes, said coupling means being engageable and disengageable with the latter of said 'ftubes by vtorsional stresses 'applied vto `,the rst ofrsaid tubes.

2. A stretcher jack, comprising a pairof telle; 1

scoped tubes adapted to be shifted axially with respect to each other, an extensible screw means i 3i. A stretcher jack, comprising a pair of telescoped tubes adapted to be shifted axially with respect to each other, an extensible screw means secured toone Aoi?, said tubes, including a nut attached to the inner wall of said tube and a headed Ascrew engaged withV said nut, a guide and coupling rodcentrally within the other of said `tubes and secured thereto, a coupling disk slidably and non=rotatably ,mounted upon said guide and .coupling rod and a couplingstress bar for intercom` nesting the head of said screw with said coupling disk. p

4. A stretcher jack according to claim, where by said headA .of said screw, said coupling disk and said stress bar, include cooperating slots for interengagement of said bar with `said head -andsaidfcoupling disk and whereby ther` one slot of said stress bar includes a...straigl'it andan inclined side wall to straighten said eou pling disk 'and to permit tilting thereof.'

5. A stretcher jack comprising a Vpair of `tele-i so dimensioned that at ,theend-of the'approachof,

the head of Vsaid screw vto said nut, @the :end ofthe tubesu-pporting said nut,Y engages Vsaid -zdisk when in its straightened/or AVer-tical position withirespect to said guide and coupling 'rod'.

JAMES MADESON ist 

